The present invention relates to a unit drawing mechanism for drawing one or more units out of an apparatus. The invention also relates to an image recorder that records an image on a sheet of paper being fed along a paper feed path, and that is fitted with a unit drawing mechanism for drawing one or more units out of the recorder.
An electrophotographic or another image recorder includes a paper feed station, a record station, and a delivery station. The record station records an image on a sheet of paper fed from the feed station and then delivers the sheet to the delivery station. For this purpose, the recorder has a paper feed path leading from the feed station through the record station to the delivery station. While a sheet of paper is fed along the feed path, a paper jam may occur. In the record station in particular, because the transfer device, the fixing device, etc. perform many kinds of processing on a sheet of paper, such as transferring a developer image to the sheet and fixing it on the sheet, the sheet warps or otherwise deforms. This reduces the feedability of the sheet and makes a paper jam liable to occur in the recorder.
Still another image recorder has a paper feed path including a reverse feed passage and records images on both sides of a sheet of paper by turning over the sheet at this passage. The inclusion of the reverse feed passage results in the paper feed path having branch points and junction points, where sheets of paper turn in other directions, so that paper jams are liable to occur there.
If a paper jam occurs on the paper feed path of an image recorder, it is necessary to stop feeding sheets of paper along the whole path and suspend image formation until all the sheets on the path are removed. For example, JP-H9-134050A discloses a conventional image recorder including a record station with walls that can be opened. The record station can be drawn out of the recorder to the front side of the recorder so that sheets of paper can be removed easily from the unit.
A proposed unit drawing mechanism includes a first drawing unit and a second drawing unit. The first drawing unit can be drawn out of an apparatus to the front side of the apparatus. The second drawing unit can be drawn from the first drawing unit to one side of the apparatus. The first drawing unit has a first feed passage as a portion of a paper feed path. The second drawing unit has a second feed passage as another portion of the feed path.
By drawing the second drawing unit from the first drawing unit, it is possible to separate the second feed passage from the first feed passage so as to expose the two passages over a wide range.
The two drawing units are free to be drawn and retracted. The second drawing unit may be drawn from the first drawing unit not drawn completely from the apparatus. The first drawing unit may be retracted into the apparatus, without the second drawing unit retracted completely into the first drawing unit. In these cases, the second drawing unit may interfere with the apparatus, so that the apparatus may malfunction or break.
A unit drawing mechanism proposed by the applicant includes a first drawing unit and a second drawing unit. The first drawing unit can be drawn out of an apparatus. The second drawing unit can be drawn from the first drawing unit. If the second drawing unit is in a situation where it may interfere with the apparatus, the two drawing units are kept from moving. This prevents the apparatus from malfunctioning or breaking.
Each of these drawing units is locked in a position automatically when it reaches the position while it is drawn or retracted. As a result, an operator clearing up a paper jam from the apparatus cannot know accurately whether the drawing units are locked. Accordingly, even if the drawing units are not locked, the operator may determine that one or both of them are locked. This may accidentally hurt the operator's fingers.
There may be a case where the operator is removing a sheet of paper from the paper feed path in this apparatus, without the first drawing unit locked. In this case, the weight of the two drawing units may move the first drawing unit into the apparatus, so that the operator's fingers may be caught between this drawing unit and the apparatus.
Such a problem arises not only with a unit drawing mechanism including two drawing units, but also with a unit drawing mechanism including only one drawing unit that can be drawn from an apparatus.
An object of the present invention is to provide a unit drawing mechanism that prevents an operator's injury by indicating the position of its drawing unit between a retracted position and an exposed position by the angular position of the lever supported on the front side of the drawing unit and adapted to be grasped by the operator when he or she draws out and pushes in the drawing unit between the retracted and exposed positions.
Another object of the invention is to provide an image recorder fitted with such a unit drawing mechanism.